Payment by Use of Identifier

1. A system comprising: one or more processors; and one or more computer-readable media storing executable instructions that, when executed by the one or more processors, cause the one or more processors to: receive, by one or more servers of a payment service system (PSS) and from a point-of-sale (POS) device associated with a merchant, a request for payment for a transaction between the merchant and a customer of the merchant, wherein the request for payment includes transaction data associated with the transaction and a customer identifier of the customer, wherein the customer identifier comprises at least one of a driver's license number of the customer, a social security number of the customer, an employee identification number of the customer, a device identifier of a customer device of the customer, a mobile application identifier of the customer, an IP address of the customer, a personal identification number (PIN) of the customer, a card verification value (CVV) of the customer, a security access code of the customer, a messaging identifier of the customer, an email address of the customer, or a biometric identifier of the customer; based on receiving the request for payment, identify, by the one or more servers of the PSS, a financial instrument and the customer device, wherein an association between the customer identifier, the financial instrument, and the device identifier is stored in a database associated with the PSS; based at least in part on the association, send, by the one or more servers of the PSS, a message to the customer device via a user interface, wherein the user interface comprises a first actuation mechanism to approve the transaction and a second actuation mechanism to cancel the transaction, and wherein the message lacks a financial instrument number of the financial instrument; receive, by the one or more servers of the PSS and from the customer device, an indication of selection of the first actuation mechanism; determine, by the one or more servers of the PSS and based on the indication of the selection of the first actuation mechanism, to approve the request for payment; and initiate, by the one or more servers of the PSS, a transfer of a payment amount associated with the request for payment to pay for the transaction, wherein the transfer is from a financial account associated with the financial instrument to a financial account associated with the merchant.

2. The system of claim 1, wherein the biometric identifier comprises input associated with a voice of the customer, a face of the customer, a fingerprint of the customer, a heartbeat of the customer, or an iris of the customer.

3. The system of claim 1, wherein the POS device comprises a first POS device, wherein the transaction comprises a first transaction, wherein the association between the customer identifier, the financial instrument, and the device identifier corresponds to a second transaction conducted at a second POS device, and wherein the first POS device and the second POS device are different POS devices.

4. The system of claim 1, wherein the database stores one or more financials instruments associated with customer identifiers.

5. A method comprising: receiving, by one or more servers of a payment service system (PSS) and from a point-of-sale (POS) device associated with a merchant of a plurality of merchants, a request for payment associated with a transaction between the merchant and a customer of the merchant, wherein the request for payment includes transaction data associated with the transaction and a customer identifier of the customer; based on receiving the request for payment, identifying, by the one or more servers of the PSS, a financial instrument and a customer device of the customer, wherein an association between the customer identifier, the financial instrument, and a device identifier of the customer device is stored in a database associated with the PSS; based at least in part on the association, sending, by the one or more servers of the PSS, a message to the customer device via a user interface, wherein the user interface comprises a first actuation mechanism to approve the transaction and a second actuation mechanism to cancel the transaction, and wherein the message lacks a financial instrument number of the financial instrument; receiving, by the one or more servers of the PSS and from the customer device, indication of selection of the first actuation mechanism; and determining, by the one or more servers of the PSS and based on the indication of the selection of the first actuation mechanism, to approve the request for payment.

6. The method of claim 5, further comprising: sending, by the one or more servers of the PSS and to the POS device, an approval message for the request for payment to be output by the POS device; and initiating, by the one or more servers of the PSS, a transfer of a payment amount associated with the request for payment from a financial account associated with the financial instrument to a financial account associated with the merchant to pay for the transaction.

7. The method of claim 5, wherein the customer identifier comprises at least one of a driver's license number of the customer, a social security number of the customer, an employee identification number of the customer, the device identifier, a mobile application identifier of the customer, an IP address of the customer, a personal identification number (PIN) of the customer, a card verification value (CVV) of the customer, a security access code of the customer, a messaging identifier of the customer, an email address of the customer, or a biometric identifier of the customer.

8. The method of claim 7, wherein the biometric identifier comprises input associated with a voice of the customer, a face of the customer, a fingerprint of the customer, a heartbeat of the customer, or an iris of the customer.

9. The method of claim 5, wherein the POS device comprises a first POS device, wherein the merchant comprises a first merchant, wherein the user interface comprises a first user interface, and wherein the customer identifier was previously provided by the customer via a second user interface presented by a second POS device associated with a second merchant of the plurality of merchants.

10. The method of claim 5, wherein the POS device is a physical POS device or an online POS device.

11. The method of claim 5, wherein the financial instrument is a credit card, a debit card, a pre-paid card, a smartcard, a biometrically identifiable instrument, or a virtual wallet.

12. The method of claim 5, further comprising: receiving, by the one or more servers of the PSS and prior to receiving the transaction data and from at least one alternate POS device associated with at least one alternate merchant of the plurality of merchants, different transaction data, the different transaction data including the customer identifier and the financial instrument; and storing, by the one or more servers of the PSS and based at least in part on verifying that the customer identifier is associated with the customer, the customer identifier associated with the financial instrument in the database such that the customer identifier is configured to be utilized at the plurality of merchants to initiate payments for a merchant transaction.

13. The method of claim 5, wherein the POS device comprises a first POS device, wherein the transaction comprises a first transaction, wherein the association between the customer identifier and the financial instrument corresponds to a second transaction conducted at a second POS device, and wherein the first POS device and the second POS device are different POS devices.

14. One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, program the one or more processors to perform acts comprising: receiving, by one or more servers of a payment service system (PSS) and from a point-of-sale (POS) device associated with a merchant, a request for payment including transaction data associated with a transaction and a customer identifier of a customer of the merchant; based on receiving the request for payment, identifying, by the one or more servers of the PSS, a financial instrument and a customer device of the customer, wherein an association between the customer identifier, the financial instrument, and a device identifier of the customer device is stored in a database associated with the PSS; based at least in part on the association, sending, by the one or more servers of the PSS, a message to the customer device via a user interface, wherein the user interface comprises a first actuation mechanism to approve the transaction and a second actuation mechanism to cancel the transaction, and wherein the message lacks a financial instrument number of the financial instrument; receiving, by the one or more servers of the PSS and from the customer device, an indication of selection of the first actuation mechanism; and determining, by the one or more servers of the PSS and based on the indication of the selection of the first actuation mechanism, to approve the request for payment.

15. The one or more non-transitory computer-readable media of claim 14, the acts further comprising: sending, by the one or more servers of the PSS and to the POS device, an approval message for the request for payment to be output by the POS device; and initiating, by the one or more servers of the PSS, a transfer of a payment amount associated with the request for payment from a financial account associated with the financial instrument to a financial account associated with the merchant to pay for the transaction.

16. The one or more non-transitory computer-readable media of claim 14, wherein the customer identifier of the customer comprises at least one of a driver's license number of the customer, a social security number of the customer, an employee identification number of the customer, the device identifier, a mobile application identifier of the customer, an IP address of the customer, a personal identification number (PIN) of the customer, a card verification value (CVV) of the customer, a security access code of the customer, a messaging identifier of the customer, an email address of the customer, or a biometric identifier of the customer.

17. The one or more non-transitory computer-readable media of claim 14, wherein the POS device is a first POS device, wherein the user interface is a first user interface, wherein the customer identifier was previously provided by the customer via a second user interface presented by a second POS device associated with a second merchant.

18. The one or more non-transitory computer-readable media of claim 14, wherein the message comprises an email.

19. The one or more non-transitory computer-readable media of claim 14, wherein the message comprises a text message or SMS message.

20. The one or more non-transitory computer-readable media of claim 14, wherein the message comprises a push notification.